Rotary pump or air-compressor.



c. R. GEVTHER. ROTARY PUMP 0B. AIB. COMPRESSOR;

APPLICATION FILED JUNE 6. 1910. I 971,188. Patented Septh 27, 1910.

4 SHEETS-SHEET 1.

o. B.; GETHER. ROTARY PUMP 0B AIB GOMPRESSOB..-

' IIIIIIIIIIIIIIIIIII B 6. 1010f 97L188. v Patented sept 27,1910.

4 SHEETS-SHEET 2.

C. R. GETHER.

ROTARY PUMP 0B. AIR COMPRESSOR.

APPLICATION FILED JUNE 6, 1910.

Patented Sept. 27, 1910.

4 SHEETS-SHEET 3.

' c. R. GETHBR. i ROTARY PUMP OE AIR COMPRESSOR.

APPLIOATIOH FILED J' um: 6. M10- Patented v 4 SHEETS-BREST 4- UNITED,sTATEs PATENT OFFICE.

CHARLES n. oETHi-iia, or MILWAUKEE, WISCONSIN.

eri-,isa

To all 'whom 'it concern: Be it lknown that l, CHARLES R. GETHER, a

i citizen of the United States, residing at Miltwo revoluble pistons areso vconnected towaukee, county of Milwaukee, and State of Wisconsin,havey invented lnew and useful Improvements in Rotary' Pumps or Air-Compressors, of which the-following is' a specification. v i

Myv invention relates to improvements in" rotary pumps or aircompressors, in which gether that they are ,caused to move alternatelyfaster and sloweraiound a common center within an inclosing cylinder,whereby the fluid to be acted upon will he caused to enter the wideninglspace between the oppoing sides of said pistons as they separate, whilethe iiuid which has previously entered betweenthe opposite sidesoof saidpistons will be simultaneously discharged and my present improvementertains more especially, amongy other things, to the peculiarconstruction and relative arrangement of the pistons, inlet and outletports and bypassesfrom being forced pastthe pistons from one of saidports to the other or from the outlet port to the space between thepistons as they begin to separate.-l l

It will be ui'iderstoodv that althou h the inlet port maybe sudicentlyopen or the admission of tluidl when` thavtwo pistons first separate,soon-"after-ffs'uch Aistons separate said rpo`rt`- becomes partial yAclosed'by the slower moving piston .lin front of the same, whereb r `thereei-` admission 'of vHuid is obstructed iorethe fast movin `piston hascompleted its= revolution, where y with this class of devices asheretofore constructed, the supplyf-'ofjuid is cut 0E oi" limitedwhereby a vpartialv vacuum is produced;- Also, that as the main outletort is not suficientl tobe discharged freelyatthe beginning oi theaccelerated' movement of .the rapidly moving piston, especallyggawhenpumping liquids, aconcussionor -`tratti',hanriinrier is.

producedas such rapidly '-'inqving piston ap-r wide open to allow t eliquid or air Specicatioii'offLetters Patent.

Application led Jun'e 6, 1910. Serial No. 565,182.

ROTARY Pinar `on ainfcoiuranss'on. I

Patented sept. '27, i910.

concussion is liable to wreck or damage the Also, that when compressingair machine. or other elastic fluids, by reason of the narrow spacebetween the outlet port and the point of` separation of the pistons theleaka e from the outlet port has a tendency to re ll the space betweensaid pistons, eX- pand, and either escape through the inlet port o rremain where it is and be again and repeatedl compressed.

One o the primary objects therefore of my present improvement is toprovide branch ports or b passes, which are so located that when t yeprimary ports are partially or wholly closed by the moving pistons, theHuid will be free to temporarily enter and escape through such branchports whereby. the pump or air compressor wili operate smoothly, easilyand with the highest eiciency, and the danger from concussion or waterhammer heretofore experienced in machines of this class is entirelyvovercome.

My invention `isexplained by reference to the accompanying drawings, inwhich- Figure i is a side view, part in section.A

Fig. 2 is an end view. Fig. 3 is a transverse section, drawn on line`:zzof Fig. 1. Fig. 4 is a longitudinal section of the pistons. Fig. 5is a perspective view of one of the pistons. Fig-6 is a Side View of oneend of the cylinder with a portion ofthe covers of the orts Vandicy-passes removed, the position o the pistons being, indicated bydotted lines. Fi s. 7 t0 14 are diagrammatic views of the cyinderypistons, ports and by-passes, show-v ing the relative-position ofthe pistons to 'each other and said ports and by-passes during onecomplete revolution of one of said pistons.

`erence numerals .throughout the several views. 1 isiaf driving shaftwhich is adapted to be driven bya pulley` 2, or in any other convenientmanner.

Af and B fare pistons of similar construc- I tion. The piston 'A isrigidly connected to the shaft 5and the piston B is connected inlike'manner to the shaft 6, and. said pistons are centrall su ported inalinement. with Seach otherl (y t e .trunnion 7. Motion is communicatefrom the shaft l to the piston inerhbe'ri through the' dierential gears8 and 9 and shaft lwhile a similar movementproaches the slowly moving,piston, which i is simultaneously, communicated to the -pis- 4Likpartsaieidentified by the same refl ton member B from the shaft 1through the differential gears 10 and 11 and shaft 6.

The relative arrangement of the two sets of differential gears 8 and 9and 10 and 11 to each other is such, that while the shaft 1 moves at auniform speed, the respective shafts and 6 and piston members A and Bmove alternately faster and slower, one of said piston members movingslowly and making` a small part of a revolution only, while the otherperforms a complete revolution, whereby the fluid between the front side'of the rapidly moving pist-on member and the rear side of the slowlymoving piston member is forced out as the rapidly moving pistonapproaches the other, while a partial vacuum is simultaneously formedbetween the rear side ofthe rapidly moving piston and the front side ofthe slowly moving piston, whereby air lor water is caused to flow intothe space between such pistons preparatory to being forced out as soonas the relative speed of said piston members is reversed. Thus the fluidacted upon is continuously7 being drawn into the space upon one side ofsaid pistons, while it is simultaneously forced from the space upon theopposing sides of said pistons. The pistons and their supporting shaftsare inclosed by the cylinder 15, and the respective ends of the cylinderare closed by the end members 16, 16, which members serve as cylinderheads, as supports for the respective ends of the shaft 1 and asbearings for the ends of the shafts 5 and 6.

29 is a support for one end of shafts 1 and 5 and 'together with thetrunnion 7 serves t0 keep said shafts 5 and 6 in alinement with eachother.

2O is an inlet port'through which uid is led to the cylinder preparatoryto being acted upon by the pistons.

21 is an outlet port through which the fluid is forced from the clinder.

1While the respective in et and outlet ports may be formed in thecylinder heads, they are preferably formed in the cylinder 15 and areadapted to be alternately opened and closed by the revolving pistons asthey pass in front of them.

In view of the fact that the inlet port 20 is partially closed by theslowly moving piston A before it is overtaken by the fast movmg pistonB, (see Fig. 3'), it becomes necessary in order to admit a full supplyof fluid into the space C to provide an auxiliary inlet port or by pass22, whereby Huid is free to enter the space C after the piston A hasentirely closed said port 20. The by pass 22 is provided with an inwardopeningcheck valve 28, which is closed by the fluid pressure within thespace C or by other means and prevents the escape of uid from such spacebefore the piston A has passed the inlet end of said by pass.l In

view also of the fact that the outlet port 21 is nearly closed by thepiston A at the beginning of the accelerated movement of the piston B, lhave provided an auxiliary port or by pass 24, whereby the fluid in thespace D is free to escape through said by pass into the port 21 untilsaid port 21 is more widely opened by the passage of the slowly movingpiston A. 25 is an outward opening check valve which serves to preventfluid which has been driven out through the port 21 by the piston B fromreturning to the cylinder through the by pass 24. In view ofthe factthat the piston A will have passed the port 21'and that said port willbe closed by the piston B before said pistons come together, a smallquantity of fluid would, unless otherwise provided for, remain trappedbetween said pistons after said port 21 is closed. It therefore followsthat unless such trapped fluid is released, it will, when a liquid,cause a concussion or so called water hammer, which is liable to breakthe pump and injuriously affect its working. Also that in case air isbeing compressed, such trapped air will be repeatedly acted upon andpermitted to expand without escaping from the cylinder. In view of thesefacts, have provided an auxiliary port 26, which is connected with theport 21 by the by pass 27, (see Fig. 6), and said port 26 is so locatedin advance of and overlapping the port 21 that such fluid as wouldotherwise become trapped in the space between said pistons A and B willbe free to pass out through said port and by-pass to t-he port 21,whereby the concussion and noise is prevented and the machine is causedto move' smoothly and with the highest e'fiency. This port is provided'with an outward o ening cheek valve 28 which prevents the u id fromrentering the space between the pistons from which it has been expelled.l

Referring briefly to the iagrammatic views shown in Figs. 7to 14, Fig. 7shows the relative position of the pistons A and B to the ports andby-passes at the be inning of the accelerated movement of the p1ston B,the inlet port 20 and the outlet port 2l being closed by the pistons Aand B, while the fluid in front of B passes out through the by-pass 24and a partial vacuum is formed in the space C between the pistons A andB. Figs. 8 and 9 show the relative position of the pistons as the inletport 20 is opened, while the fluid is being forced out both through theport 21 and by-pass 24 and admitted through the port 20. F ig. 10 showsthe relative position of the pistons after both inlet and outlet portsare partially open and both by passes 22 and 24 are also opened. Figs.11 and 12 show the relative position of the pistons to each other andthe ports after the piston B has closed the by pass 24. Fig. 13 showsthe relative position of the pistons to each other after the outlet port21 is closed entirely at which point the fluid which becomes .trappedbetween said pistons, passes out through the port 26, and thence back tothe port 21 through the by pass 27 until both istons come close togetheras shown in ig. 14, while Fig. 14 shows the position of the piston Awhen and after it has been overtaken by t-he piston B, and until thepistons again begin t-o separate at which point the relative position ofsaid pistons is completely reversed. As soon as the piston B has thuscompleted its revolution and overtaken the piston A, the speed of thepiston A will in like manner be accelerated until it overtakes thepiston B and the `movement t-hus describedwill be continuously repeated;

lt will be understood that by thus using the several auxiliary ports andby passes, I am enabled to make the main ports 20 and 21 comparativelynarrow vwithout restricting or interfering with the free passage offluid to and from the cylinder andthat by thus making such portscomparatively narrow, a larger surface area is provided between saidports than it would be possible to provide with larger ports, wherebythere is less danger than there might otherwise be of the fluid, whichis under pressure, from escaping from one port to the 'other past saidpistons or from the outlet port to the openinflr space between thepistons. For

example, if the port 21 were to be increased in width to correspond withthe width of the auxiliary port 26 and port 21 combined f( as'inightotherwise be required to prevent the trapping of fluid between saidpistons l as they come together) Ithere would not rc-` main enoughsurface area between the 'inlet and outlet ports to'prevent the escape.-of fluid from one port to the other or from the outlet port to theopening space between the pistons, while by forming the auxiliary portsand by asses and providing the same with check va ves as shown, l amenabled as stated to locate said main ports ata 'sufficient distanceapart to prevent such escape of fluid and the loss of thereto.

While my device is adapted to. be used both as an-air compressor and asa liquid pump for brevity of description it is hereinafter referred toin the claims as a pump.

Having thus described my invention, what l claim as new, and desire tosecure by Letters Patent, is v 1. ln a pump, the combination with acylinder, of two pistons extending from its axis to its circumferenceand from end to end and having substantially equal circumferential Widthmounted therein, and adapted to rotate about said axis, means foi`continuously rotating the pistons in the same direction lat alternatelylfaster and slower power incident speeds so that each shall move fasterwhile the other 'moves slower, with such am litudes of the movements ofeachv kind t at adjacent faces of the pistons will alternately approacheach other until they are close together and recede from each otheruntil the of the pistons at practically the beginning Y of the recedingmovement and constantly closed to the approaching faces and the outletport is opened between the a preaching faces of the pistonscuntil the enof the approaching movement and is constantly closed to the recedingfaces, the ports being separated by a considerable spaceon the interiorsurface of the cylindery which is covered by` the pistons when they comeclose together.

2. In a pump," the combination with a cylinder, of two istons extendin/gfrom its axis to its circum erence, and' fromnend to end and havingsubstantially equal circumferential width mounted therein, and adaptedto rotate about said axis, means for continuously rotating the pistonsin the same direc tion at alternately faster and slower speeds' so thateach shall move faster while the other moves slower, with suchamplitudes of the movements of e `h kind that adjacent faces of theistons y'will alternately approach each ot er until they are closetogether and recede from each other until'the opposite faces are closetogether, inlet and outlet orts communicating-with said cylinder a aptedto be alternatelyT-opened and closed by said pistons asthe'latterrevolve in front of them, .anadditional outletport :located at a pointslightly Ifin advance of and overlapping said main-I outlet port at andbefore the 'unctional'pointgpf said pistons, a check valve located insaid''port and a b pass leading from said advanced port bac to said mainoutletl ort adapted to permit between said pistons to escape after saidmain outletport is closed by the fast moving pist/0n. y v l 3. In apump, the combination with a cylinder, of two pistons extending from itsaxis to its circumference and from end to end and havingsubstantiallyequalV circumferential width mounted therein, and adapted to rotateabout said axis, means for continuously rotating the pistons in thesamedirection at alternately faster and slower speeds so that eachshall movefaster while the other moves slower with such amplitudes of themovements o each kind that adjacent faces the fluid which wou dotherwise be trapped of the pistons will alternately approach each otheruntil they are close together and recede from each other` until theopposite faces are close together, an auxiliary inlet port adapted toadmit fluid between said pistons after the main inlet port is partiallyclosed by the slowly moving piston and a check valve located in saidauxiliary inlet port.

4. In a pump, the combination with a cylinder, of two pistons extendingfrom itsv axis to its circumference and from end to end and havingsubstantially equal circumferential width mounted therein, and adaptedto rotate about said axis, means for ,continuously rotating the pistonsin the same direction at alternately faster and slower speeds so thateach shall move faster While the other moves slower, with suchamplitudes ofthe movements of each kind that adjacent faces of thepistons will alternately approach each other until they are closetogether and recede from each other until the opposite faces are closetogether, an outlet port and by pass adapted to permit of the escape offluid from between said pistons before the main outlet port has beenfully opened by the passage of the slowly moving piston and a checkvalve adapted to close said Voutlet port.

In a pump, the combination with a cylinder, of two pistons extendingfrom its axis to its circumference and from end to end and havingsubstantially equal circum` ferential widthv mounted therein, andadapted to rotate about said axis, means-for continuously rotating thepistons .in the same direction at alternately faster and slower l speedsso that each shall move faster while theother moves slower, with suchamplitudes of the movements of each kind that adjacent faces ofthepistons will alternately approach each other until they are closetogether and recede from each other until the opposite faces are 'closetogether, inlet and outlet ports communicating with said cylinderadapted to be alternately opened and-closed by said pistons as thelatter revolve in front of them, an auxiliary inletport, a check valvelocated in said inlet port adapted to admit fluid lbetween said pistonsafter the main inlet port is practically closed by the slowly movingpiston, an outlet port and by pass, a check valve located in said` loutlet port adapted to permit ofthe escape of fluid before the mainoutlet port is fully opened, and an additional outlet port located atapoint slightly in advance of and overlapping said main outlet port atand just before the junctional point of said pistons a check valvelocated in said additional port and a by pass leading from saidadditional port back to said ma1n outlet port and adapted -to permit thefluid which is trapped between said pistons to escape after of saiddriving shaft and one of said piston l supporting shafts, the other endmember being adapted to support the other end of said driving shaft andtogether with the trunnion to support the other piston supporting shaftwhereby said pistons and piston supporting shafts are supported andretained in alinement with each-other.

In testimony whereof I 'afx my signature in the presence' of twowitnesses.

. CHARLES R. GETHER. Witnesses:

JAS. B. ERWIN,

R. L. FARRING'ION.

